Efficacy

Pronunciation

• IPA: /ˈɛf.ɪ.kÉ™.si/

Origin

From Old French efficace, from Late Latin efficacia ("efficacy"), from Latin efficax ("efficacious"); see efficacious.

Full definition of efficacy

Noun

1. (uncountable) Ability to produce a desired amount of a desired effect.

Synonyms

• efficacity

Related terms

• effect
• effective
• effectiveness
• effectivity
• effector
• effectual
• effectuate
• efficacious
• efficacity
• efficiency
• efficient